TEMA required?

[Bill3752]

When is it required to design a heat exchanger to TEMA standards? I am installing a condenser on top of a condensate tank to knock down steam being relieved from the tank.

 

[gr2vessels]

Short answer, when your exchanger is configured as a shell and tube heat exchanger (most likely by your process engineer design). The condenser could also be configured in many other ways, excluding the applicability of TEMA.
However, the term 'tank' you are using is a bit vague, at the best. Tank is a storage equipment designed to API 650/620 or similar and is not used for steam generation. Perhaps you are talking about a pressure vessel relieving some steam which you wish to condensate in a knock-out drum or similar. In that case you don't need a heat exchanger at all.
Could you come back with some more details?
gr2vessels

 

[rmw]

TEMA will tell you how to construct the Hx but not how to design it. Consensers are designed differently than straight S&T Hx's, although there are plenty of straight S&T Hx's out there limping along as pretty fair condensers.

Condensers generally need an air removal section so that the non condensables don't air bind the heat transfer surfaces.

rmw

 

[Bill3752]

Thanks for your responses. The current process includes a low pressure condensate tank, from which some steam flashes. (operating pressure < 1psig, design pressure is 75 psig). The client is seeking to eliminate the steam plume, and recover some heat value as a side benefit. I am currently planning on runnning the current 10" tank vent to the shell side of an exchanger - demin water on the tube side.

I have designed and had constructed several large exchangers - always to TEMA. A "steam system" vendor gave me a quote for a condenser to handle this, but when I asked them to send me a TEMA spec sheet they balked - stating that their fabricator could not handle - and expect the cost to triple. None of this makes sense to me.

 

[Christine74]

Condensers are normally designed per HEI (Heat Exchange Institute) standards, not TEMA.

http://www.heatexchange.org/pub/default.htm

-Christine

 

[rmw]

An HEI member, Graham -

http://www.graham-mfg.com

has an excellent product (Obviously not TEMA though) in their spiral "Heliflow" heat exchanger for this application. Rummage around their site and you will find it. In fact, you will find a lot of good stuff on their site about condensers in general.

rmw

 

[gr2vessels]

Bill3752,
It is unusual, as you can see from the above replies, the condenser to be configured as a shell and tube exchanger. However, if you insist on this design, the 75 psi design pressure would warrant a TEMA + ASME VIII Div 1 design. Also demin water on the cooling side??? I can see that at least to you the bad economical times went past leaving daisy petals on your foot path. If you can afford the cost, ditch the miserable carbon steel tubes, the Superduplex ones will last you a life time (otherwise the demin water will corrode the proverbial out of your tubes).
You might be right, the little cheap Heliflow will never look as impressive as a massive, expensive shell and tube exchanger. Imagine the shiny saddles chromium plated....! Stainless Steel anchor bolts, pink painted nuts...By the way, the word nuts reminds me of something...
cheers,
gr2vessels